No abstract

No abstract

No abstract

No abstract

Water soluble fullerene derivatives I and II were shown to behave as promising neuroprotective agents that improve cognitive functioning in animals.

Patterns of the interaction between water soluble polysubstituted fullerene derivatives (PFDs) and the lipid bilayer of phosphatidylcholine liposomes were investigated by applying triplet and fluorescent probes. Objective quantitative criteria have been proposed for the evaluation of membranotropic action of chemical substances, notably, fullerene derivatives that quench fluorescent probes with different localizations within the membrane. Thus, the defined criteria are the rate constants for the quenching of the fluorescence of triplet probes and the equilibrium constants for PFD probe complexes, which characterize their stability. The localization of PFDs in the membrane was determined by comparing rate constants for the quenching of eosin phosphorescence and equilibrium constants for PFD-chromophore complexes. In addition, the effi ciency of the interaction of PFDs with various sites of the phospholipid membrane has been seen to depend on the charge of addends that are attached to the polysubstituted derivatives. N Br NH 2 H 2 N Br O COO Br O Br Br − O Br Eosin Y 2,7 Br proflavine Pyrene Fig. 1. Luminescent probes used in the study.

This paper shows the biological effects of cationic binuclear tetranitrosyl iron complex with penicillamine ligands (TNIC–PA). Interaction with a model membrane was assessed using a fluorescent probes technique. Antioxidant activity was studied using a thiobarbituric acid reactive species assay (TBARS) and a chemiluminescence assay. The catalytic activity of monoamine oxidase (MAO) was determined by measuring liberation of ammonia. Antiglycation activity was determined fluometrically by thermal glycation of albumine by D-glucose. The higher values of Stern–Volmer constants (KSV) obtained for the pyrene located in hydrophobic regions (3.9 × 104 M−1) compared to KSV obtained for eosin Y located in the polar headgroup region (0.9 × 104 M−1) confirms that TNIC–PA molecules prefer to be located in the hydrophobic acyl chain region, close to the glycerol group of lipid molecules. TNIC–PA effectively inhibited the process of spontaneous lipid peroxidation, due to additive contributions from releasing NO and penicillamine ligand (IC50 = 21.4 µM) and quenched luminol chemiluminescence (IC50 = 3.6 μM). High activity of TNIC–PA in both tests allows us to assume a significant role of its radical-scavenging activity in the realization of antioxidant activity. It was shown that TNIC–PA (50–1000 μM) selectively inhibits the membrane-bound enzyme MAO-A, a major source of ROS in the heart. In addition, TNIC–PA is an effective inhibitor of non-enzymatic protein glycation. Thus, the evaluated biological effects of TNIC–PA open up the possibility of its practical application in chemotherapy for socially significant diseases, especially cardiovascular diseases.

No abstract